COMPUTER SYSTEM DESIGN

                                                 COMPUTER SYSTEM DESIGN

Systems design is the process of defining the architecture, components, modules, interfaces, and data for asystem to satisfy specified requirements. Systems design could be seen as the application of systems theory toproduct development. There is some overlap with the disciplines of systems analysissystems architecture andsystems engineering

If the broader topic of product development "blends the perspective of marketing, design, and manufacturing into a single approach to product development,"[3] then design is the act of taking the marketing information and creating the design of the product to be manufactured. Systems design is therefore the process of defining and developing systems to satisfy specified requirements of the user.
Until the 1990s systems design had a crucial and respected role in the data processing industry. In the 1990sstandardization of hardware and software resulted in the ability to build modular systems. The increasing importance of software running on generic platforms has enhanced the discipline of software engineering.
Object-oriented analysis and design methods are becoming the most widely used methods for computer systems design.[citation needed] The UML has become the standard language in object-oriented analysis and design.[citation needed] It is widely used for modeling software systems and is increasingly used for high designing non-software systems and organizations.[citation needed]

Architectural design[edit]

The architectural design of a system emphasizes on the design of the systems architecture which describes thestructurebehavior, and more views of that system.

Logical design[edit]

The logical design of a system pertains to an abstract representation of the data flows, inputs and outputs of the system. This is often conducted via modelling, using an over-abstract (and sometimes graphical) model of the actual system. In the context of systems design are included. Logical design includes ER Diagrams i.e. Entity Relationship Diagrams.

Physical design[edit]

The physical design relates to the actual input and output processes of the system. This is laid down in terms of how data is input into a system, how it is verified/authenticated, how it is processed, and how it is displayed as In Physical design, the following requirements about the system are decided.
  1. Input requirement,
  2. Output requirements,
  3. Storage requirements,
  4. Processing Requirements,
  5. System control and backup or recovery.
Put another way, the physical portion of systems design can generally be broken down into three sub-tasks:
  1. User Interface Design
  2. Data Design
  3. Process Design
User Interface Design is concerned with how users add information to the system and with how the system presents information back to them. Data Design is concerned with how the data is represented and stored within the system. Finally, Process Design is concerned with how data moves through the system, and with how and where it is validated, secured and/or transformed as it flows into, through and out of the system. At the end of the systems design phase, documentation describing the three sub-tasks is produced and made available for use in the next phase.
Physical design, in this context, does not refer to the tangible physical design of an information system. To use an analogy, a personal computer's physical design involves input via a keyboard, processing within the CPU, and output via a monitor, printer, etc. It would not concern the actual layout of the tangible hardware, which for a PC would be a monitor, CPU, motherboard, hard drive, modems, video/graphics cards, USB slots, etc. It involves a detailed design of a user and a product database structure processor and a control processor. The H/S personal specification is developed for the proposed system.

Configuration design is a kind of design where a fixed set of predefined components that can be interfaced (connected) in predefined ways is given, and an assembly (i.e. designed artifact) of components selected from this fixed set is sought that satisfies a set of requirements and obeys a set of constraints.
The associated design configuration problem consists of the following three constituent tasks:
  1. Selection of components,
  2. Allocation of components, and
  3. Interfacing of components (design of ways the components interface/connect with each other).
Types of knowledge involved in configuration design include:
  • Problem-specific knowledge:
    • Input knowledge:
      • Requirements
      • Constraints
      • Technology
    • Case knowledge
  • Persistent knowledge (knowledge that remains valid over multiple problem solving sessions):
    • Case knowledge
    • Domain-specific, method-independent knowledge
    • Method-specific domain knowledge
    • Search-control knowledge

See also[edit]


Modular design, or "modularity in design", is a design approach that subdivides a system into smaller parts called modules or skids, that can be independently created and then used in different systems. A modular system can be characterized by functional partitioning into discrete scalable, reusable modules, rigorous use of well-defined modular interfaces and making use of industry standards for interfaces.
Besides reduction in cost (due to lesser customization, and less learning time), and flexibility in design, modularity offers other benefits such as augmentation (adding new solution by merely plugging in a new module), and exclusion. Examples of modular systems are carscomputersprocess systems, and high rise buildings. Earlier examples include loomsrailroad signaling systems, telephone exchangespipe organs and electric power distribution systems. Computers use modularity to overcome changing customer demands and to make the manufacturing process more adaptive to change (see modular programming).[1] Modular design is an attempt to combine the advantages of standardization (high volume normally equals low manufacturing costs) with those of customization. A downside to modularity (and this depends on the extent of modularity) is that modular systems are not optimized for performance. This is usually due to the cost of putting up interfaces between modules.[citation needed]

Proper inter-modular design[edit]

Recognizing that excessive inter-module dependencies are an indicator of poor software design, a system should be intended to be loosely coupled to avoid unnecessary dependencies.[citation needed] Thus, inter-modular design should be easy to work with because modules can be easily understood in isolation, and changes or extensions to functionality would be easily localized.

Modular design in cars[edit]

Aspects of modular design can be seen in cars or other vehicles to the extent of there being certain parts to the car that can be added or removed without altering the rest of the car.
A simple example of modular design in cars is the fact that, while many cars come as a basic model, paying extra will allow for "snap in" upgrades such as a more powerful engine or seasonal tires; these do not require any change to other units of the car such as the chassis, steering or exhaust systems.

Modular design in buildings[edit]

Main article: Modular building

Modular workstations
Modular design can be seen in certain buildings. Modular buildings (and also modular homes) generally consist of universal parts (or modules) that are manufactured in a factoryand then shipped to a build site where they are assembled into a variety of arrangements.[2]
Modular buildings can be added to or reduced in size by adding or removing certain components. This can be done without altering larger portions of the building. Modular buildings can also undergo changes in functionality using the same process of adding or removing modular components.
For example, an office building can be built using modular parts such as walls, frames, doors, ceilings, and windows. The office interior can then be partitioned (or divided) with more walls and furnished with desks, computers, and whatever else is needed for a functioning workspace. If the office needs to be expanded or redivided to accommodate employees, modular components such as wall panels can be added or relocated to make the necessary changes without altering the whole building. Later on, this same office can be broken down and rearranged to form a retail space, conference hall or any other possible type of building using the same modular components that originally formed the office building. The new building can then be refurnished with whatever items are needed to carry out its desired functions.
Other types of modular buildings that are offered from a company like Allied Modular are a guardhouse, machine enclosure, press boxconference room, two-story building, clean room and much more applications.[3]
Many misconceptions are held around modular buildings.[4] In reality modular construction is a viable method of construction for quick turnaround and fast growing companies. Industries that would benefit from include: healthcare, commercial, retail, military, and multi-family/student housing.

Modular design in computer hardware[edit]


Modular computer design
Modular design in computer hardware is the same as modular design in other things (e.g. cars, fridges, even furniture). The idea is to build computers with easily replaceable parts that use standardized interfaces. This technique allows you to upgrade certain aspects of the computer easily without having to buy another computer altogether.
A computer is actually one of the best examples of modular design - typical modules are power supply unitsprocessorsmainboardsgraphics cards,hard drivesoptical drives, etc. All of these parts should be easily interchangeable as long as you use parts that support the same standard interface as the part you replaced.

See also[edit]

Platform technology is a term for technology that enables the creation of products and processes that support present or future or past development. It establishes the long-term capabilities of research & development institutes. It can be defined as a structural or technological form from which various products can emerge without the expense of a new process/technology introduction.
In computing platforms, for example, computer hardware serves as platform for an operating system which in turn is a platform for Enterprise Infrastructure Software which in turn is a platform for application softwareTransport infrastructure similarly serves as platform for vehicles.
A pharmaceutical platform technology can ease future research work. Suppose if a researcher formulates a new dosage form using a certain drug along with the optimized amount of excipients, then the same excipients can be used by other researchers, just changing the active ingredient and acquiring a new drug delivery dosage form. This would ensure less time and money being spent on finalizing the concentration, amount, type, etc. of excipients used. Thus, more stress can be given on studies related to the active drug. For example, if an eye dropsolution uses certain polymers as excipients, then a platform technology can be established whereby other researchers can use the optimized polymers, and just change the active drug, leading to formulation of a whole new drug-dosage, with less money and time spent on the selection of the excipients.
Thus, Platform technology creates a platform for the researchers to formulate new drug-dosages, without working much on the already optimized excipients.
Automobile platforms allow a motor company such as VW to release several vehicles built upon a common chassis (platform) with different engines, interiors and form factors, for the same or different brands within the company (VW, Audi, Skoda, Seat etc.).
A platform technology increases the ease of manufacture. Fewer parts/sub-assemblies need be designed, made, and kept in inventory, and assembly workers don't need so much training.

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